Diet: Organic fruits, vegetables, and whole grains to give the body plenty of vitamins, minerals, enzymes, and other nutrients. The fruits and vegetables are low in sodium (salt) and high in potassium.

Supplementation: The addition of certain substances to the diet to help correct cellmetabolism (the chemical changes that take place in a cell to make energy and basic materials needed for the body's life processes).

What is the history of the discovery and use of the Gerson therapy as a complementary or alternative treatment for cancer?

The Gerson therapy was named after Dr. Max B. Gerson (1881-1959), who first used it to treat his migraine headaches. In the 1930's, Dr. Gerson’s therapy became known to the public as a treatment for a type of tuberculosis (TB). The Gerson therapy was later used to treat other conditions, including cancer.

What is the theory behind the claim that the Gerson therapy is useful in treating cancer?

The Gerson therapy is based on the idea that cancer develops when there are changes in cell metabolism because of the buildup of toxic substances in the body. Dr. Gerson said the disease process makes more toxins and the liver becomes overworked. According to Dr. Gerson, people with cancer also have too much sodium and too little potassium in the cells in their bodies, which causes tissue damage and weakened organs.

The goal of the Gerson therapy is to restore the body to health by repairing the liver and returning the metabolism to its normal state. According to Dr. Gerson, this can be done by removing toxins from the body and building up the immune system with diet and supplements. The enemas are said to widen the bile ducts of the liver so toxins can be released. According to Dr. Gerson, the liver is further overworked as the treatment regimen breaks down cancer cells and rids the body of toxins. Pancreatic enzymes are given to decrease the demands on the weakened liver and pancreas to make enzymes for digestion. An organic diet and nutritional supplements are used to boost the immune system and support the body as the regimen cleans the body of toxins. Foods low in sodium and high in potassium are said to help correct the tissue damage caused by having too much sodium in the cells.

How is the Gerson therapy administered?

The Gerson therapy requires that the many details of its treatment plan be followed exactly. Some key parts of the regimen include the following:

Drinking 13 glasses of juice a day. The juice must be freshly made from organic fruits and vegetables and be taken once every hour.

Have any clinical trials (research studies with people) of the Gerson therapy been conducted?

Most of the published information on the use of the Gerson therapy reports on retrospective studies (reviews of past cases). Dr. Gerson published case histories (detailed reports of the diagnosis, treatment, and follow-up of individual patients) of 50 of his patients. He treated several different types of cancer in his practice. The reports include Dr. Gerson's notes, with some X-rays of the patients over time. The follow-up was contact with patients by mail or phone and included anecdotal reports (incomplete descriptions of the medical and treatment histories of one or more patients).

In 1947 and 1959, the National Cancer Institute (NCI) reviewed the cases of a total of 60 patients treated by Dr. Gerson. The NCI found that the available information did not prove the regimen had benefit.

The following studies of the Gerson therapy were published:

In 1983-1984, a retrospective study of 38 patients treated with the Gerson therapy was done. Medical records were not available to the authors of the study; information came from patient interviews. These case reviews did not provide information that supports the usefulness of the Gerson therapy for treating cancer.

In 1990, a study of a diet regimen similar to the Gerson therapy was done in Austria. The patients received standard treatment along with the special diet. The authors of the study reported that the diet appeared to help patients live longer than usual and have fewer side effects. The authors said it needed further study.

In 1995, the Gerson Research Organization did a retrospective study of their melanoma patients who were treated with the Gerson therapy. The study reported that patients who had stage III or stage IV melanoma lived longer than usual for patients with these stages of melanoma. There have been no clinical trials that support the findings of this retrospective study.

A case review of 6 patients with metastatic cancer who used the Gerson therapy reported that the regimen helped patients in some ways, both physically and psychologically. Based on these results, the reviewers recommended that clinical trials of the Gerson therapy be conducted.

Have any side effects or risks been reported from use of the Gerson therapy?

Reports of three deaths that may be related to coffee enemas have been published. Taking too many enemas of any kind can cause changes in normal blood chemistry, chemicals that occur naturally in the body and keep the muscles, heart, and other organs working properly.

Is the Gerson therapy approved by the U.S. Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

The Gerson therapy has not been approved by the FDA for use as a treatment for cancer or any other disease.

For most cancer patients, nutrition guidelines include eating a well-balanced diet with plenty of fruits, vegetables, and whole-grain products. However, general guidelines such as these may have to be changed to meet the specific needs of an individual patient. Patients should talk with their health care providers about an appropriate diet to follow. Information about diet during cancer treatment is also available from the Cancer Information Service (1-800-4-CANCER) and in the PDQ summary on Nutrition in Cancer Care.

Changes to This Summary (01/07/2015)

The PDQcancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Changes were made to this summary to match those made to the health professional version.

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about the use of Gerson therapy in the treatment of people with cancer. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Clinical trials are listed in PDQ and can be found online at NCI's Web site. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Permission to Use This Summary

PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”

Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 2,000 scientific images.

Contact Us

More information about contacting us or receiving help with the Cancer.gov Web site can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the Web site’s Contact Form.

General CAM Information

Complementary and alternative medicine (CAM)—also referred to as integrative medicine—includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.

Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.

Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any therapeutic approach, because some complementary and alternative therapies may interfere with their standard treatment or may be harmful when used with conventional treatment.

Evaluation of CAM Approaches

It is important that the same rigorous scientific evaluation used to assess conventional approaches be used to evaluate CAM therapies. The National Cancer Institute (NCI) and the National Center for Complementary and Alternative Medicine (NCCAM) are sponsoring a number of clinical trials (research studies) at medical centers to evaluate CAM therapies for cancer.

Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a rigorous scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have undergone rigorous evaluation. A small number of CAM therapies originally considered to be purely alternative approaches are finding a place in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) Consensus Conference in November 1997, acupuncture has been found to be effective in the management of chemotherapy-associated nausea and vomiting and in controlling pain associated with surgery. In contrast, some approaches, such as the use of laetrile, have been studied and found ineffective or potentially harmful.

The NCI Best Case Series Program, which was started in 1991, is one way CAM approaches that are being used in practice are being investigated. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records and related materials to OCCAM. OCCAM conducts a critical review of the materials and develops follow-up research strategies for approaches deemed to warrant NCI-initiated research.

Questions to Ask Your Health Care Provider About CAM

When considering complementary and alternative therapies, patients should ask their health care provider the following questions:

What side effects can be expected?

What are the risks associated with this therapy?

Do the known benefits outweigh the risks?

What benefits can be expected from this therapy?

Will the therapy interfere with conventional treatment?

Is this therapy part of a clinical trial?

If so, who is sponsoring the trial?

Will the therapy be covered by health insurance?

To Learn More About CAM

National Center for Complementary and Alternative Medicine (NCCAM)

The National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.

NCCAM and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM's PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the Web sites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.) CAM on PubMed is available through the NCCAM Web site. It can also be accessed through NLM PubMed bibliographic database by selecting the "Limits" tab and choosing "Complementary Medicine" as a subset.

Office of Cancer Complementary and Alternative Medicine

The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via the NCI Web site.

National Cancer Institute (NCI) Cancer Information Service

U.S. residents may call the NCI Cancer Information Service toll free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 am to 8:00 pm. A trained Cancer Information Specialist is available to answer your questions.

Food and Drug Administration

The Food and Drug Administration (FDA) regulates drugs and medical devices to ensure that they are safe and effective.